New Refractor Choosing Help

[hadyn42]

Hello

Could someone help me choose a suitable refractor please? I do really like my SW ED80 and use it as my grab and go telescope and use it at quite a few public outreach events!!

I am in the market for a 4" or 5" refractor and I do have a budget of £1.500. I am really torn between the Explore Scientific ED APO 127mm F/7.5 Essential  or the SW ED120. I do have a suitable mount for either one so no problems there. I am afraid I am getting to a certain age when lifting and carrying it out my 10" Dob out to my car even when its in two pieces  leaves feeling somewhat tied.

I would really like to hear your opinions and any reviews regarding these telescopes please?  Or maybe another make of refractor that could be suitable too?

Best regards,

Hadyn - Isle of Man

 

 

[Uplooker]

Hi Hadyn,

Hope you are keeping well. What targets do you hope to use the "new" scope for?

[John]

Following my recent experiences with my ED120 and comparing it with my Takahashi 100 and TMB / LZOS 130 I'm even more of a fan of Skywatchers 4.7" ED doublet

I think the ED120 is somewhat lighter and less demanding on mountings than the ES 127 as well.

[Paul73]

I'm more than happy with my ED120. The build quality is excellent. Like the ED80, the stock focuser may need a bit of tinkering with to get it working at its best.

Compared to the ED80, it provides some cracking planetary views, splits a double nicely and the extra grunt helps on the brighter clusters. It must be noted that, save for the odd quick look at star parties, I haven't got much experience with this size frac; but I am a happy owner and had an ED80 which was sold to finance the 120.

Hope that this helps.

Paul

[spaceboy]

"Explore Scientific ED APO 127mm F/7.5 Essential  or the SW ED120."

I may be wrong and possibly thinking of a different scope, but I was led to believe the ES triplets have FPL51 glass or at least the equivalent. The ED120 has FPL53 which is considered the better of the two.

Also the ES being a triplet may well be noticeably heavier and more challenging to mount than the ED120 which in truth could be mistaken for a smaller scope than it is.

I think the choice for myself would be based on the £500 difference in price (if your buying new?) as I doubt very much your going to see a great deal of difference visually between the two.

[Sirius Starwatcher]

Hi Haydn Had exactly the same thoughts as you. Over the past six months I've read every review I could find on the Fracs that your looking at.  How about this as a consideration. I know it's not a triple but gets some great reviews. This is the one I've settled for and I am on the waiting list for delivery which I believe is due in the next two three weeks. Best  of luck with your choice.

https://www.tringastro.co.uk/starwave-152-v2-red-tube-achromat-refractor-telescope-7921-p.asp

 

[ollypenrice]

The ED120 is light and ridiculously good, optically, for its price. It might benefit from a better focuser like the Baader diamant steeltrack.

Olly

[Saganite]

If not the Skywatcher ED120, then how about the Altair Wave Series 130 f7 Triplet that has just come up on AB&S for £1500. 

[sloz1664]

There is a nice Altair Astro 130 Triplet on AB&S for £1500

Steve

Atair Wave Series 130 F7 ED Triplet APO

[gorann]

First I have to say I have no experience with the SW scope. Since SW seems more widespread than ES in the UK, and most comments here are about the SW scope, I thought I should say that I have had an ES 127ED for two years now and am very happy with it. I use it for astrophotography. Like you I read everything I could find on the net about it and alternatives, like the SW 120ED. My impression was that the ES was significantly better corrected since it was a true triplet apo, and that it is not possible to correct a doublet as good as a triplet. The ES has a slightly cheaper ED glass, but the difference regards the refractive index of the ED glass (and not the "quality") and for an f/7.5 triplet I understood that Ohara FPL-53 was overkill and FPL-51 was enough (or the equivalent Hoya glass used by ES).  Here is one of the reviews that finally made me settle for the ES:

http://www.skynews.ca/review-explore-scientific-127ed-apo-refractor/

And here is an image taken through my ES 127ED with a Canon 60Da

[John]

14 minutes ago, gorann said:

...... significantly better corrected since it was a true triplet apo, and that it is not possible to correct a doublet as good as a triplet. The ES has a slightly cheaper ED glass, but the difference regards the refractive index of the ED glass (and not the "quality") and for an f/7.5 triplet I understood that Ohara FPL-53 was overkill and FPL-51 was enough (or the equivalent Hoya glass used by ES).  Here is one of the reviews that finally made me settle for the ES:

http://www.skynews.ca/review-explore-scientific-127ed-apo-refractor/

 

It is possible for an FPL-53 doublet to be better corrected for CA than an FPL-51 (or similar glass) triplet. I've seen a number of reviews comparing the ED120 to ES and Meade triplets where this has been the case.

Both exellent scopes though

Telescope Services have a triplet model now that uses an FPL-53 element:

http://www.teleskop-express.de/shop/product_info.php/info/p6679_TS-Optics-PHOTOLINE-130-mm-f-7-Triplet-APO---FPL53---2-5-inch-RPA-focuser.html

 

 

[Stu]

1 hour ago, John said:

It is possible for an FPL-53 doublet to be better corrected for CA than an FPL-51 (or similar glass) triplet. I've seen a number of reviews comparing the ED120 to ES and Meade triplets where this has been the case.

Both exellent scopes though

Telescope Services have a triplet model now that uses an FPL-53 element:

http://www.teleskop-express.de/shop/product_info.php/info/p6679_TS-Optics-PHOTOLINE-130-mm-f-7-Triplet-APO---FPL53---2-5-inch-RPA-focuser.html

 

 

I would tend to agree with this. I've looked through a 127 Triplet and did not think the correction was as good as my Tak (fluorite doublet) or the 120ED.

[gorann]

3 minutes ago, John said:

It is possible for an FPL-53 doublet to be better corrected for CA than an FPL-51 (or similar glass) triplet. I've seen a number of reviews comparing the ED120 to ES and Meade triplets where this has been the case.

Both exellent scopes though

 

 

Aha, but was that high-f refractors, like f/7.5? I know I read somewhere that for a f/7.5 triplet there was not any need for such a high refractive index as the FPL-51 (f/6  5" scopes probably need FPL-53). It has all to do with how you mate the ED glass with the other two lenses. Here is a tread discussing these things (unfortunately very very very long):

https://www.cloudynights.com/topic/335776-fpl-53-vs-fpl-51/

[gorann]

1 hour ago, John said:

It is possible for an FPL-53 doublet to be better corrected for CA than an FPL-51 (or similar glass) triplet. I've seen a number of reviews comparing the ED120 to ES and Meade triplets where this has been the case.

Both exellent scopes though

Telescope Services have a triplet model now that uses an FPL-53 element:

http://www.teleskop-express.de/shop/product_info.php/info/p6679_TS-Optics-PHOTOLINE-130-mm-f-7-Triplet-APO---FPL53---2-5-inch-RPA-focuser.html

 

 

By the way, that TS triplet could probably be the best buy of them all. I expect their 2.5" focuser is a bit better than the ES one.

[John]

3 hours ago, gorann said:

Aha, but was that high-f refractors, like f/7.5? I know I read somewhere that for a f/7.5 triplet there was not any need for such a high refractive index as the FPL-51 (f/6  5" scopes probably need FPL-53). It has all to do with how you mate the ED glass with the other two lenses. Here is a tread discussing these things (unfortunately very very very long):

https://www.cloudynights.com/topic/335776-fpl-53-vs-fpl-51/

Both F/7.5 refractors - the ED120 and the Meade / ES 127 triplets.

It's true that the mating element is as important as the ED element and also the figure, spacing and mounting of the lens elements all make a difference.

 

[Rick_It]

If you can raise your budget, the APM 140 is definitely a scope you will never regret to have purchased. For visual, I would prefer a doublet but with slightly better mechanics than the SW 120 ED, at least a sliding dewshiled for example.

[mikeDnight]

The SW 120ED would be my first choice for a ED Apo in your budget. I really like the Equinox 120ED version, though optically they are identical. Very easy to carry and not overly demanding on the mount, the SW120ED will keep pace with some of the best refractors on most nights. I love them!

Mike

[catburglar]

ED120 - no doubt- unless you really want something for imaging- you'll almost never see a bad review of one.  I waited months for a used SW ED120 to come up for sale.....in the end I got a Meade Mak178 which I'm very happy with. Now I see on this on ABS UK (note I'm not affiliated with the seller) please buy it before I do! http://www.astrobuysell.com/uk/propview.php?view=126037

[Commanderfish]

I have the ES 127 Apo and absolutely love it.  Sharpest scope I've ever looked through.  Great planetary views, lovely for sweeping wide fields too.  A very useful feature is the built in handle which you can easily bolt a camera or even a Vixen mount on to.  I tend to mount an ES 80 Apo onto it for super-wide field views   

[hadyn42]

Hello All

Thank you very much indeed guys for all your input which is very much appreciated....

By doing all the searching for a suitable refractor it did my head in, but I  think now I am almost  getting to a final decision, ha, ha. Its now between the Equinox 120 or the ES 127ED, with the Equinox out in front... I will let you know when I have pushed the button, so to speak!

Garry: I did some phoning around about  the Red 152mm V2 Starwave and I was told it could be between 2 to 3 months before they are back on the selves..

Kindest regards,

Hadyn - Isle of Man

 

[John]

I think either would be a fine scope Hadyn - looking forward to hearing about what you choose and seeing some photos !